Distance and torsion angle information can be gleaned from various 2D NMR methods, such as 2D NOESY and different 2D COSY experiments. This geometrical information can then be incorporated in form of restraints for molecular mechanics and molecular dynamics simulations to yield high resolution structures. The restrained molecular dynamics calculations lead to a structure reflecting the time-average inherent in the NMR derived constraints. My recent calculations employed a new type of pseudo-potential for the restraints with which the restraint values will be enforced as an average over a period of time and not every single step as it is commonly done. These type of calculations have been majorly improved through the incorporation of explicit solvent for both conventional restraints and the weighted time-average restraints mentioned above. After working on DNA problems for many years, most of my research efforts are now dedicated to the study of the interaction of medium size RNA molecules and proteins. My main emphasis will be on a protein-RNA model system for the signal recognition particle, a ribonucleoprotein system that direct protein translocation. Furthermore, I am working on the structure elucidation of an RNA fragment which is a highly conserved part of the viral RNA of HIV-1. In collaboration with the group of Dr. D. V. Santi, I have started working on the interaction between the T-loop of transfer-RNA and a RNA-methylating enzyme (RUMT). I utilize MidasPlus to scrutinize all NMR-derived distances by comparing them with the pertinent distances of canonical DNA structures. A new feature in MidasPlus, noeshow, allows to display all NMR-derived distance restraints directly with any set of the according coordinates. The degree of violation is directly indicated by color coding. All molecular dynamics simulations are usually viewed as a movie using MDM or DISPLAY. This turned out to be the some efficient way to monitor structural transitions occurring in those calculations. For my RNA work, a great deal of model building was done using fragments from the Brookhaven Protein Databank crystal structures. Here the wonderful stereo facilities of the CGL lab are absolutely necessary for all the docking that is needed to build up larger molecules. The use of the Computer Graphics Laboratory has been indispensable in many ways for performing our challenging research.